Method for producing optoelectronic semiconductor devices and optoelectronic semiconductor device

ABSTRACT

The invention relates to a method for producing a plurality of optoelectronic semiconductor components, including the following steps: preparing a plurality of semiconductor chips spaced in a lateral direction to one another; forming a housing body assembly, at least one region of which is arranged between the semiconductor chips; forming a plurality of fillets, each adjoining a semiconductor chip and being bordered in a lateral direction by a side surface of each semiconductor chip and the housing body assembly; and separating the housing body assembly into a plurality of optoelectronic components, each component having at least one semiconductor chip and a portion of the housing body assembly as a housing body, and each semiconductor chip not being covered by material of the housing body on a radiation emission surface of the semiconductor component, which surface is located opposite a mounting surface. The invention also relates to a semiconductor component.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/866,890 filed May 5, 2020, now allowed, which is acontinuation of U.S. patent application Ser. No. 16/240,584 filed Jan.4, 2019, which is a divisional of, and claims the benefit of andpriority to, U.S. patent application Ser. No. 15/036,413, filed May 12,2016, which is a United States National Phase under 35 U.S.C. § 371 ofinternational Application No. PCT/EP2014/073369 filed on Oct. 30, 2014,which claims priority to German Patent Application No. 102013112549.2,filed Nov. 14, 2013, all of which are hereby incorporated by referencein their entirety for all purposes.

BACKGROUND

Arrangements are for example known for semiconductor devices such aslight-emitting diodes in which the semiconductor chips provided forgenerating radiation are mounted in prefabricated packages. It isdifficult to miniaturize such arrangements to produce particularlycompact LEDs.

SUMMARY

One object is to provide a method for producing optoelectronicsemiconductor devices reliably and compactly and with high outcouplingefficiency. Furthermore, such a semiconductor device is to be provided.

These objects are achieved inter alia respectively by a method and asemiconductor device according to the independent claims. Configurationsand convenient aspects constitute the subject matter of the dependentclaims.

A method is provided for producing a plurality of optoelectronicsemiconductor devices.

According to at least one embodiment of the method, the method comprisesa step in which a plurality of semiconductor chips is provided. The inparticular optoelectronic semiconductor chips are spaced from oneanother in a lateral direction. For example, the semiconductor chips arepresent on an auxiliary carrier. The auxiliary carrier may be offlexible construction, for example in the form of a film, or rigid.

According to at least one embodiment of the method, said methodcomprises a step in which a package body assembly is formed, which isarranged at least in part between the semiconductor chips. The packagebody assembly is produced in particular by means of a molding method.The term molding method here covers all production methods in which amolding composition is introduced into a predetermined mold and inparticular is subsequently cured. In particular, the term molding methodencompasses casting, injection molding, transfer molding and compressionmolding.

The package body assembly and thus the package body formed from thepackage body assembly is formed in particular to be radiation-opaque forthe radiation emitted or to be detected by the semiconductor chip duringoperation of the semiconductor device.

In one variant configuration, the package body is radiation-reflective,i.e. the package body has a reflectivity of at least 55%. Thereflectivity preferably amounts to at least 80%.

In one alternative variant configuration, the package body isradiation-absorbent. In other words, the package body absorbs at least55% of the incident radiation. The package body is formed for example bya black material.

The semiconductor chips in particular comprise a semiconductor body withan active region provided for generating radiation. The semiconductorbody, in particular the active region, contains for example a III-Vcompound semiconductor material. Furthermore, the semiconductor chip inparticular comprises a carrier, on which the semiconductor body isarranged. The carrier is for example a growth substrate for thesemiconductor layers of the semiconductor body. Alternatively, thecarrier is different from a growth substrate for the semiconductorlayers of the semiconductor body. In this case, the carrier serves inmechanical stabilization of the semiconductor body, such that the growthsubstrate is not necessary therefor and may be removed.

A semiconductor chip in which the growth substrate has been removed isalso known as a thin-film semiconductor chip.

According to at least one embodiment of the method, the method comprisesa step in which a plurality of fillets are formed, which each adjoin asemiconductor chip. In the lateral direction the fillets are eachdelimited by a side face of the respective semiconductor chip and thepackage body assembly. In the region of the fillets, the package bodyassembly thus does not directly adjoin the side face of thesemiconductor chips.

In the vertical direction the fillets may extend over the entire heightof the semiconductor chip or only over a part of the semiconductor chip.In case of doubt, a vertical direction is understood to mean a directionwhich extends perpendicular to the mounting surface of the semiconductordevice. Accordingly, a lateral direction runs parallel to the mountingsurface.

The fillets are provided in particular to increase the outcouplingefficiency of the semiconductor chips.

According to at least one embodiment of the method, the method comprisesa step in which the package body assembly is singulated into a pluralityof optoelectronic semiconductor devices, wherein each singulatedsemiconductor device has at least one semiconductor chip and part of thepackage body assembly as package body.

The package bodies arise from the package body assembly, i.e. only onsingulation and thus at a time when the semiconductor chips are alreadylocated in the package body.

According to at least one embodiment of the method, on singulation ofthe package body assembly the semiconductor chips are each free ofpackage body material on a semiconductor device radiation exit faceopposite a mounting surface. Furthermore, the semiconductor chips on themounting surface may be free of the package body material. On theradiation exit face and optionally also on the mounting surface there isthus no package body material apart possibly from residues resultingfrom manufacture. The semiconductor chips arranged in the package bodyand connected mechanically stably to the package body are thus embeddedin the package body only in the lateral direction. In the verticaldirection, the semiconductor chips may extend right through the packagebody.

In at least one embodiment of the method for producing a plurality ofoptoelectronic semiconductor devices, a plurality of semiconductor chipsare provided which are spaced from one another in a lateral direction. Apackage body assembly is formed which is arranged at least in partbetween the semiconductor chips. A plurality of fillets are formed,which each adjoin a semiconductor chip and which are delimited in thelateral direction by a side face of the respective semiconductor chipand the package body assembly. The package body assembly is singulatedinto a plurality of optoelectronic semiconductor devices, wherein eachsemiconductor device comprises at least one semiconductor chip and apart of the package body assembly as package body and wherein thesemiconductor chips are free of package body material on a radiationexit face of the semiconductor device opposite a mounting surface.

By means of the fillet, efficiency of outcoupling from the semiconductorchip may be increased in the case of a semiconductor device in the formof a radiation emitter. The maximum lateral extent of the filletpreferably amounts to at most 100 μm, particularly preferably at most 50μm. Compact configuration of the semiconductor device is thus madesimpler.

According to at least one embodiment of the method, the semiconductorchips are each free of package body material on the mounting surface.The semiconductor chips are thus accessible on the mounting surface, forexample for thermal contacting and/or electrical contacting.

According to at least one embodiment of the method, the fillet isradiation-transmissive. In particular, the fillet is transparent or atleast translucent for the radiation generated or to be detected by thesemiconductor device during operation. The generated radiation may becoupled into the fillet at a side face of the semiconductor chip andexit from the fillet at the radiation exit face.

According to at least one embodiment of the method, the fillet has areflectivity of at least 80%. In particular, the fillet has a higherreflectivity than the package body material. In this case, theabsorption losses may be reduced by means of the fillet.

According to at least one embodiment of the method, to form the filletsthe semiconductor chips are encapsulated prior to formation of thepackage body assembly in such a way with an encapsulating material thatthe side faces of the semiconductor chips are at least partly coveredand the encapsulating material is encapsulated on formation of thepackage body assembly by a molding composition for the package bodyassembly. Formation of the fillets, in particular definition of thegeometric shape of the fillets, thus proceeds at least in part beforethe package body assembly is formed. At those points at which theencapsulating material is present, the molding composition for thepackage body assembly does not directly adjoin the side face of thesemiconductor chips to be encapsulated.

According to at least one embodiment of the method, the semiconductorchips are arranged on an auxiliary carrier during formation of thepackage body assembly and/or during formation of the plurality offillets. Prior to singulation of the package body assembly, theauxiliary carrier may be removed.

A film, for instance a self-adhesive film, or a rigid carrier areexamples of suitable auxiliary carriers.

According to at least one embodiment of the method, the encapsulatingmaterial is applied such that it in each case at least partly covers theside faces of the semiconductor chips and the auxiliary carrier. Onapplication of the encapsulating material, the semiconductor chips havethus already been arranged on the auxiliary carrier. The encapsulatingmaterial is applied in particular onto the semiconductor chips such thatthe major face, remote from the auxiliary carrier, of the semiconductorchips remains free of the encapsulating material. The encapsulatingmaterial may for example be printed on or applied by means of adispenser.

According to at least one embodiment of the method, the encapsulatingmaterial is applied to an auxiliary carrier and the semiconductor chipsare pressed into the encapsulating material such that the encapsulatingmaterial covers the side faces of the semiconductor chips at least inpart. In this case, the encapsulating material may serve at the sametime to fasten the semiconductor chips to the auxiliary carrier. Thethickness of the encapsulating material is adjusted in this respectpurposefully such that the side faces of the semiconductor chips arewetted completely or at least in part with the encapsulating material.The major face of the semiconductor chips remote from the auxiliarycarrier remains free of the encapsulating material.

According to at least one embodiment of the method, the encapsulatingmaterial is a filler material, which remains in the semiconductordevices. The filler material is a radiation-transmissive material, forexample. The filler material may furthermore contain a radiationconversion material, which is provided for at least partial radiationconversion of radiation generated in the semiconductor chips.

Alternatively, the filler material may have a reflectivity of at least80% for the radiation to be generated and/or received by thesemiconductor chip. A reflective fillet allows the prevention or atleast the reduction of radiation absorption at the package body, inparticular even in the case of an absorbent package body.

According to at least one embodiment of the method, the encapsulatingmaterial is an auxiliary material which is removed once the package bodyassembly has been formed. The auxiliary material thus serves merely toform the plurality of fillets during formation of the package bodyassembly. In other words, the geometric shape of the subsequent filletsis fixed by the auxiliary material. The auxiliary material thus preventsthe molding composition from completely covering the side faces of thesemiconductor chips to be encapsulated during formation of the packagebody assembly. A suitable auxiliary material is an adhesive which iscomparatively easy to remove, for example by the action of temperature,a solvent and/or a wet chemical etching method.

According to at least one embodiment of the method, formation of theplurality of fillets proceeds after formation of the package bodyassembly. The molding composition of the package body assembly may thuscompletely cover the side faces of the semiconductor chips prior toformation of the fillets. To form the fillets, material of the packagebody assembly is for example removed. This proceeds for example by meansof coherent radiation, for instance laser radiation. Formation of thefillets preferably proceeds such that the molding composition of thepackage body assembly adjoins the side faces of the semiconductor chipswith a surface coverage of at most 50% of the side faces.

According to at least one embodiment of the method, the fillet is filledwith a filler material after formation of the package body assembly.Compared with an unfilled fillet, the refractive index difference at theside face of the semiconductor chip may be reduced by means of thefiller material.

According to at least one embodiment of the method, the semiconductorchips are covered over on formation of the package body assembly and thepackage body assembly is then thinned, such that the semiconductor chipsare uncovered in places. The major face, remote from the auxiliarycarrier, of the semiconductor chips is thus initially covered over bythe material of the package body assembly and then uncovered again.Thinning of the package body assembly may for example proceedmechanically, for instance by means of grinding or lapping.

Through uncovering of the semiconductor chips, semiconductor devices maybe produced in which the waste heat generated in the semiconductor chipsduring operation may be dissipated directly at the mounting surface ofthe semiconductor devices, without the heat having to pass through thematerial of the package body.

According to at least one embodiment, an optoelectronic semiconductordevice comprises a mounting surface and a radiation exit face oppositethe mounting surface. The semiconductor device additionally comprises asemiconductor chip provided for generating and/or receiving radiation.

According to at least one embodiment of the optoelectronic semiconductordevice, the semiconductor device comprises a package body whichsurrounds the semiconductor chip in a lateral direction, wherein thesemiconductor chip is free of package body material at the radiationexit face. The package body for example does not project or at leastprojects only insignificantly, for example by at most 10 μm, beyond thesemiconductor chip in the vertical direction on the opposite side fromthe mounting surface.

According to at least one embodiment of the optoelectronic semiconductordevice, a side face of the semiconductor chip is adjoined by a fillet,which is delimited in a lateral direction extending parallel to themounting surface by the side face of the semiconductor chip and thepackage body.

In at least one embodiment of the optoelectronic semiconductor device,the semiconductor device comprises a mounting surface and a radiationexit face opposite the mounting surface. The semiconductor devicecomprises a semiconductor chip provided for generating and/or receivingradiation. The semiconductor device comprises a package body whichsurrounds the semiconductor chip in a lateral direction. Thesemiconductor chip is free of the package body material at the radiationexit face. A side face of the semiconductor chip is adjoined by afillet, which is delimited in a lateral direction running parallel tothe mounting surface by the side face of the semiconductor chip and thepackage body.

The package body may adjoin the semiconductor chip directly in places inthe lateral direction or be spaced from the semiconductor chip at allpoints over the entire circumference of the semiconductor chip. Thepackage body is preferably at a distance of at most 10 μm from thesemiconductor chip at at least one point. In this way, a particularlycompact semiconductor device may be obtained.

According to at least one embodiment of the semiconductor device, thefillet extends over the entire circumference of the semiconductor chip.The package body thus, at least in places in the vertical direction,does not directly adjoin the semiconductor chip over the entirecircumference.

According to at least one embodiment of the semiconductor device, thefillet tapers in the direction of the mounting surface when viewed fromthe radiation exit face. For example, the fillet comprises convexcurvature when viewed from the radiation exit face.

Radiation exiting from the side face of the semiconductor chip may inthis way be efficiently deflected towards the normal to the radiationexit face.

According to at least one embodiment of the semiconductor device, thefillet contains a radiation conversion material. The radiationconversion material is for example provided for converting primaryradiation generated in the semiconductor chip with a first peakwavelength into secondary radiation with a second peak wavelengthdifferent from the first peak wavelength. For example, the semiconductordevice is provided for generating a mixed light, in particular a mixedlight that appears white to the human eye.

The above-described method for producing optoelectronic semiconductordevices is particularly suitable for producing the optoelectronicsemiconductor device. Features listed in connection with the method maytherefore also be used for the semiconductor device and vice versa.

Further features, configurations and convenient aspects are revealed bythe following description of the exemplary embodiments in conjunctionwith the figures.

Identical, similar or identically acting elements are provided with thesame reference numerals in the figures.

The figures and the size ratios of the elements illustrated in thefigures relative to one another are not to be regarded as being toscale. Rather, individual elements and in particular layer thicknessesmay be illustrated on an exaggeratedly large scale for greater ease ofdepiction and/or better comprehension.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures:

FIGS. 1A to 1E, 2A to 2E and 3A to 3E each show an exemplary embodimentof a method for producing optoelectronic semiconductor devices on thebasis of intermediate steps illustrated in each case in schematicsectional view; and

FIGS. 4A and 4B show an exemplary embodiment of a semiconductor devicein plan view (FIG. 4B) and associated sectional view (FIG. 4A).

DETAILED DESCRIPTION

FIGS. 1A to 1E show a first exemplary embodiment of a method forproducing a plurality of optoelectronic semiconductor devices. As shownin FIG. 1A, a plurality of semiconductor chips 2 are arranged on anauxiliary carrier 5. The description below relates to radiation-emittingsemiconductor devices, by way of example. The semiconductor chips arefor example luminescent diode semiconductor chips, for instancelight-emitting diode semiconductor chips. In contrast thereto, thesemiconductor devices may however also be provided for receivingradiation and for example comprise a semiconductor chip in the form of aphotodiode.

In a vertical direction the semiconductor chips 2 extend between a front28 and a back 29. The front is that side of the semiconductor chipsthrough which the radiation generated in the semiconductor chips exitsduring operation of the subsequent semiconductor devices. Thesemiconductor chips are arranged in such a way on the auxiliary carrier5 that the front faces the auxiliary carrier.

A self-adhesive film is for example suitable for the auxiliary carrier5. Alternatively, the semiconductor chips may also be fastened by meansof a temporary adhesive, by means of a wax, by means of “Expancelmicrospheres” or by means of a silicone. The agent bringing aboutadhesion of the semiconductor chips may be provided solely under thesemiconductor chips, such that the auxiliary carrier between thesemiconductor chips is uncovered. Alternatively, the auxiliary carriermay be covered over its entire surface.

A filler material 40 is applied to the auxiliary carrier 5 such that thefiller material covers the side faces 20 of the semiconductor chipscompletely or at least in part. This may proceed for example by means ofa dispenser. Optionally, the auxiliary carrier 5 may be patterned in thelateral direction in such a way that it comprises wetting areas 51. Thewetting areas display higher wettability than the regions arrangedbetween the wetting areas 51 of the surface of the auxiliary carrier 5facing the semiconductor chips 2. For example, the wetting areas 51 maybe hydrophilic and the further regions of the surface of the auxiliarycarrier 5 may be hydrophobic. For example, silicone may be distinguishedby hydrophobic properties.

The geometric shape of the fillets is thus not determined by apredefined mold, but rather self-organized.

In particular, the geometric shape may be adjusted by the materialproperties of the filler material 40, for example surface tension andviscosity, and the wettability of the auxiliary carrier and of thesemiconductor chips 2 with the filler material.

The lateral extent of the fillet 4 reduces from the front 28 of thesemiconductor chip towards the back 29. In the exemplary embodimentshown, the auxiliary carrier 5 is free of the filler material in places,between adjacent semiconductor chips 2.

Then the semiconductor chips 2 are encapsulated, with the fillets 4adjoining the semiconductor chips 2 in the lateral direction, by amolding composition to form a package body assembly 30 (FIG. 1C). In theexemplary embodiments shown, the package body assembly 30 also coversthe back 29 of the semiconductor chips 2. Formation of the package bodyassembly 30 proceeds for example by means of a molding method.

In a subsequent production step, the package body assembly 30 may bethinned from the side remote from the auxiliary carrier 5, for exampleby means of a mechanical method such as grinding.

Instead of covering over the semiconductor chips 2 on the back 29 andsubsequently thinning the package body assembly 30, the package bodyassembly may also be formed such that the backs 29 of the semiconductorchips 2 are uncovered. To this end, a film-assisted molding method maybe used, for example.

FIG. 1D shows the package body assembly 30 with the semiconductor chips2 embedded therein after removal of the auxiliary carrier 5. Afterremoval of the auxiliary carrier 5, the front 28 of the semiconductorchip is accessible, for example for electrical contacting of thesemiconductor chips. To simplify representation, this is not shown inthe figures and, like possible configurations of the semiconductorchips, is explained with reference to FIGS. 4A and 4B.

For singulation into semiconductor devices 1, the package body assembly30 may be divided along singulation lines 7. This may for exampleproceed mechanically, for instance by means of sawing, chemically, forexample by means of etching, and/or by means of coherent radiation, forinstance by laser ablation.

In the case of a radiation-transmissive fillet 4, radiation may alsoexit through the side faces 20 of the semiconductor chip 2 when thesemiconductor device is in operation. A boundary surface 31 arisingbetween the fillet 4 and the package body 3 resulting from the packagebody assembly may form a reflector face, by which the laterally exitingradiation may be focused.

The filler material 40 may furthermore be mixed with a radiationconversion material, which converts radiation generated when thesemiconductor chips 2 are in operation, for example blue radiation, atleast in part into secondary radiation, for example into yellowradiation.

In the case of a radiation-transmissive fillet 4, the boundary surface31 is reflective and for example has a reflectivity of at least 80%. Forexample, the package body 3 is formed by a material which is mixed withwhite pigments.

Alternatively, the fillet 4 may itself also be formed from a fillermaterial which has a high reflectivity for the radiation generated inthe semiconductor chip, for example a reflectivity of at least 80%. Thefillet thus also protects the package body 3 from damage by radiationgenerated in the semiconductor chip during operation.

The material for the package body 3 may be selected irrespective of theoptical properties and of the radiation stability thereof. For example,a black epoxide material (“black epoxy”) is suitable in this case forthe package body 3. Such a material is particularly cheaply availabledue to its being widely used in the electronics industry and isdistinguished by good processability.

The back 29 of the semiconductor chips 2 is uncovered at a mountingsurface 15 of the semiconductor device 1, such that the waste heatgenerated in the semiconductor chip can be efficiently dissipated viathe mounting surface 15 during operation. In contrast thereto, it ishowever also feasible for the material of the package body 3 to coverthe back 29 of the semiconductor chip 2.

On the side remote from the mounting surface, the package body does notproject or at least does not project significantly beyond thesemiconductor chip in the vertical direction. A particularly compactarrangement is thereby made simpler.

The second exemplary embodiment shown in FIGS. 2A to 2E correspondssubstantially to the first exemplary embodiment described in connectionwith figures IA to IE. Unlike in the first exemplary embodiment, anauxiliary material 41 is applied to the auxiliary carrier 5, before eventhe semiconductor chips 2 are fastened to the carrier 5 (FIG. 2A).Application of the auxiliary material may proceed for example by meansof printing or a jetting method.

Then, the semiconductor chips 2 are pressed into the auxiliary material41, such that the auxiliary material 41 wets the side faces 20 of thesemiconductor chips 2. A meniscus 410 forms in the auxiliary material 41between adjacent semiconductor chips 2. The auxiliary material 41 has asmaller vertical extent in the region of the meniscus 410 than in theregion in which the auxiliary material adjoins the semiconductor chips 2(FIG. 2B).

The auxiliary material 41 thus also serves in fastening thesemiconductor chips 2 to the auxiliary carrier 5.

A material which is particularly suitable as the auxiliary material 41is a material which can be simply and reliably removed in a subsequentmethod step without the risk of damage to the further elements.

As shown in FIG. 2C, the semiconductor chips 2 and the auxiliarymaterial 41 are then encapsulated by a molding composition to form apackage body assembly 30. This may take place as described in connectionwith FIG. 1C. As a result of the auxiliary material 41, the package bodyassembly 30 does not adjoin the semiconductor chips 2, or at least doesso with a surface coverage of at most 20%, preferably of at most 10%.

FIG. 2D shows a stage in the method in which the auxiliary carrier 5 andthe auxiliary material 41 have been removed. Depending on the auxiliarymaterial, suitable means of removing said auxiliary material are forexample a solvent, an etching method or heat treatment, in which theauxiliary material 41 melts.

The fillet 4 formed by means of the auxiliary material 41 may then befilled with a filler material 40. This may proceed for example by meansof a metering method, for instance by means of a dispenser or by meansof a molding method.

In terms of the optical properties thereof, the fillet 4 may beconfigured as described in connection with FIG. 1A. Alternatively, it isalso feasible for the fillet 4 not to be filled with a filler material,but rather to remain empty. This maximizes the refractive indexdifference at the side face 20 of the semiconductor chip 2. As a resultof total reflection, the fraction of the radiation which may exitthrough the side face 20 of the semiconductor chips 2 is thus minimized.

The third exemplary embodiment shown in FIGS. 3A to 3E correspondssubstantially to the first exemplary embodiment described in conjunctionwith FIGS. 1A to 1E. Unlike in the first exemplary embodiment, thesemiconductor chips 2 provided on the auxiliary carrier 5 (FIG. 3A) arefirstly encapsulated by a molding composition to form a package bodyassembly 30, such that the molding composition adjoins the side faces 20of the semiconductor chips 20 over the entire surface. In contrast tothe first exemplary embodiment, the semiconductor chips 2 are placedsuch that the back 29 of the semiconductor chips faces the auxiliarycarrier 5.

As shown in FIGS. 3B and 3C, formation of the package body assembly 30may in turn proceed such that the semiconductor chips 2 are initiallycompletely embedded in the molding composition for the package bodyassembly 30 and then the package body assembly is thinned such that thefront 28 of the semiconductor chips 2 is uncovered.

Material of the package body assembly 30 which adjoins the side faces 20of the semiconductor chips is then removed in places. This may beachieved for example by laser ablation. In the vertical direction thefillet 4 extends only over part of the side face 20 of the semiconductorchips 2, such that material of the package body assembly 30 adjoins theside face 20 even after formation of the fillet 4. The larger the regionin which the package body assembly 30 adjoins the semiconductor chips 2,the easier it is to achieve a mechanically stable connection between thesemiconductor chips 2 and the package body assembly 30. On the otherhand, outcoupling efficiency may be improved by greater verticalextension of the fillets 4. The surface coverage with which the packagebody assembly 30 covers the side faces 20 of the semiconductor chip 2after formation of the fillets 4 preferably amounts to at most 50%.

After formation of the fillets 4, the latter may be filled or not filledas described in connection with FIG. 2E.

An exemplary embodiment for a semiconductor device is shown in FIG. 4Bin plan view and in schematic sectional view along line AA′ in FIG. 4A.The semiconductor device 1 comprises a semiconductor chip 2. Thesemiconductor chip 2 comprises a semiconductor body 21 with an activeregion 22 provided for generating radiation and a substrate 25. A mirrorlayer 26 is formed on the back 29 of the semiconductor chip 2. Themirror layer may for example be a metallic mirror layer or a Braggreflector with a plurality of dielectric layers. On a front 28 thesemiconductor chip 2 comprises two lands for electrical contacting ofthe semiconductor chip (not illustrated explicitly).

The substrate 25 is for example the growth substrate for thesemiconductor body 21. A suitable substrate is for example aradiation-transmissive substrate such as sapphire or silicon carbide. Inthe lateral direction the semiconductor chip 2 is enclosed by a packagebody 3. A fillet 4 is formed between the package body 3 and thesemiconductor chip 2. The fillet 4 surrounds the semiconductor chip 2 inthe lateral direction over the entire circumference. Furthermore, thefillet 4 has a lateral extent which decreases as the distance from theradiation exit face 10 of the semiconductor device 1 increases. Thefillet 4 may be radiation-transmissive or reflective, as described inconnection with FIG. 1E.

On a mounting surface 15 opposite the radiation exit face 10, thesemiconductor device 1 comprises a first contact 61 and a second contact62. By applying an external electrical voltage between these contacts,charge carriers may be injected from different sides into the activeregion 22 and there recombine with emission of radiation. The firstcontact 61 and the second contact 62 are each electrically conductivelyconnected with the semiconductor chip 2 by way of through-vias 63through the package body 3 and connecting conductors 64. The connectingconductors 64 extend in the lateral direction beyond the side face 20 ofthe semiconductor chip 2 and cover part of the package body 3. In thedescribed exemplary embodiment the connecting conductor 64 takes theform of a coating. In contrast thereto, a wire bond connection mayhowever also be used. On the side opposite the mounting surface 15, thesemiconductor device 1 may comprise a radiation conversion element (notillustrated explicitly).

The geometric arrangement of the contacts and contact guidance to thesemiconductor chip 2 may however be varied within limits. For example, asemiconductor chip may also be used which has a front and a rear land.In this case only a through-via 63 is necessary. A semiconductor chipwith two rear lands is also conceivable. For example, the semiconductorchip 2 may also take the form of a thin-film semiconductor chip with anelectrically conductive substrate 25.

To determine the achievable efficiency, simulations were performed whichwere based on a semiconductor chip with a transparent substrate 25, suchthat radiation could also to a considerable degree be coupled out of theside face 20 of the semiconductor chips. A comparison structure, inwhich the semiconductor chip in each case adjoins a material with areflectivity of 92% at the back and at the side faces, was used as thestarting point for the simulations. A radiation conversion material wasprovided on the front of the semiconductor chips. By using a filletsurrounding the semiconductor chip, the boundary surface of whichfillet, remote from the semiconductor chip, is inclined relative to theside face of the semiconductor chip by an angle of 45°, and which filletis filled with a radiation conversion material, an increase inefficiency of 6% may be achieved.

If the fillet is not filled with a radiation conversion material, butrather with a silicone with a high refractive index of around 1.5, theefficiency can be increased by around 6.25% compared with the comparisonstructure. The simulations were in each case based on a semiconductorchip height of 150 μm.

The described fillet thus allows a significant increase in theefficiency of the semiconductor device to be achieved in a technicallysimple manner.

The invention is not restricted by the description given with referenceto the exemplary embodiments. Rather, the invention encompasses anynovel feature and any combination of features, including in particularany combination of features in the claims, even if this feature or thiscombination is not itself explicitly indicated in the claims or theexemplary embodiments.

What is claimed:
 1. An optoelectronic semiconductor device with amounting surface and a radiation exit face opposite the mountingsurface, wherein the semiconductor device comprises a semiconductor chipprovided for generating radiation; the semiconductor device comprises apackage body which surrounds the semiconductor chip in a lateraldirection; the semiconductor chip is free of package body material atthe radiation exit face; a side face of the semiconductor chip isadjoined by a fillet, the fillet extending at least in regions betweenthe side face of the semiconductor chip and the package body; thesemiconductor chip comprises a growth substrate and a semiconductor bodyarranged on the growth substrate; and the optoelectronic semiconductordevice comprises a first contact and a second contact on the mountingsurface, wherein at least one of the first contact and the secondcontact is electrically conductively connected to the semiconductor chipby way of a through-via.
 2. The semiconductor device according to claim1, wherein the fillet extends over an entire circumference of thesemiconductor chip.
 3. The semiconductor device according to claim 1,wherein the fillet tapers in the direction of the mounting surface whenviewed from the radiation exit face.
 4. The semiconductor deviceaccording to claim 1, wherein the package body at least in regions doesnot extend between the semiconductor chip and the mounting surface whenseen along a vertical direction running perpendicular to the mountingsurface.
 5. The semiconductor device according to claim 1, wherein thefillet is filled with a radiation-transmissive material.
 6. Thesemiconductor device according to claim 1, wherein the fillet is filledwith a material that does not comprise a radiation conversion material.7. The semiconductor device according to claim 1, wherein the packagebody comprises a material that is mixed with white pigments.
 8. Thesemiconductor device according to claim 1, wherein the package body hasa reflectivity of at least 55% for the radiation to be emitted by thesemiconductor chip.
 9. The semiconductor device according to claim 1,wherein an interface between the fillet and the package body comprises aconvex curvature when viewed from the radiation exit face.
 10. Thesemiconductor device according to claim 1, wherein the semiconductorchip comprises a mirror layer.
 11. The semiconductor device according toclaim 10, wherein the mirror layer is a metallic mirror layer formed ona back of the semiconductor chip.
 12. The semiconductor device accordingto claim 1, wherein the fillet extends over an entire height of thesemiconductor chip when seen along a vertical direction runningperpendicular to the mounting surface.
 13. The semiconductor deviceaccording to claim 1, wherein the fillet extends only over a part of thesemiconductor chip when seen along a vertical direction runningperpendicular to the mounting surface.
 14. The semiconductor deviceaccording to claim 1, wherein the semiconductor chip is electricallycontacted via two lands, the two lands being arranged on a side of thesemiconductor body facing away from the growth substrate.
 15. Thesemiconductor device according to claim 1, wherein the semiconductordevice comprises a radiation conversion element on a side of thesemiconductor chip opposite the mounting surface.
 16. The semiconductordevice according to claim 1, wherein the first contact and the secondcontact are each electrically conductively connected to thesemiconductor chip by way of a through-via.
 17. The semiconductor deviceaccording to claim 16, wherein the through-vias are electricallyconnected to the semiconductor chip by connecting conductors, theconnecting conductors extending in the lateral direction beyond sidefaces of the semiconductor chip.
 18. The semiconductor device accordingto claim 17, wherein the connecting conductors are formed as a coating.19. The semiconductor device according to claim 1, wherein a material ofthe package body covers a rear side of the semiconductor chip inregions.
 20. The semiconductor device according to claim 1, wherein thepackage body is a part of a package body assembly.
 21. The semiconductordevice according to claim 1, wherein the package body is formed from acasted molding composition.
 22. The semiconductor device according toclaim 1, wherein the fillet directly adjoins the side face of thesemiconductor chip and the package body.
 23. An optoelectronicsemiconductor device with a mounting surface and a radiation exit faceopposite the mounting surface, wherein the semiconductor devicecomprises a semiconductor chip provided for generating radiation; thesemiconductor device comprises a package body which surrounds thesemiconductor chip in a lateral direction; the semiconductor chip isfree of package body material at the radiation exit face; a side face ofthe semiconductor chip is adjoined by a fillet, the fillet extending atleast in regions between the side face of the semiconductor chip and thepackage body; the optoelectronic semiconductor device comprises a firstcontact and a second contact on the mounting surface, wherein at leastone of the first contact and the second contact is electricallyconductively connected to the semiconductor chip by way of athrough-via; the fillet extends over an entire circumference of thesemiconductor chip; the fillet tapers in the direction of the mountingsurface when viewed from the radiation exit face; and the package bodyat least in regions does not extend between the semiconductor chip andthe mounting surface when seen along a vertical direction runningperpendicular to the mounting surface.